Device and method for triggering an occupant protection system in the event of a motor vehicle rollover

Abstract

A device and method for triggering an occupant protection system when a motor vehicle tilts about a longitudinal axis includes a rate-of-rotation sensor, an inclination sensor, which can be a mechanical inclination switch, and a triggering device. The rate-of-rotation sensor detects a rotation rate about the longitudinal axis and generates an output signal. The inclination sensor detects motor vehicle inclination and generates an output signal. The mechanical inclination switch serves as safing sensor. The triggering device activates an occupant protection system based upon the rotation and the inclination output signals. The occupant protection system triggers only when both the rate-of-rotation sensor indicates a rotary movement greater than or equal to a specific value and the inclination sensor indicates an inclination angle greater than or equal to a given value. The triggering device blocks an activation of the occupant protection system when the inclination signal indicates a tilted position of the vehicle lasting longer than a predetermined time interval even if the rotation signal subsequently indicates a motor vehicle tilting movement about the longitudinal axis.

We claim:  
     
       1. A device for triggering an occupant protection system when a motor vehicle tilts about a motor vehicle longitudinal axis, comprising: 
       a rate-of-rotation sensor detecting a rate of motor vehicle rotation about a longitudinal axis of the motor vehicle and for generating a rotation output signal;  
       an inclination sensor for detecting motor vehicle inclination and for generating an inclination output signal; and  
       a triggering device for activating an occupant protection system based upon the rotation output signal and the inclination output signal,  
       said triggering device connected to said rate-of-rotation sensor and said inclination sensor and configured to trigger an occupant protection system only when both said rate-of-rotation sensor outputs a signal indicating a rotary movement greater than a specific value and said inclination sensor outputs a signal indicating a motor vehicle inclination angle greater than a given value, said triggering device blocking an activation of the occupant protection system when the inclination output signal indicates a tilted position of the motor vehicle lasting longer than a predetermined time interval even if the rotation output signal subsequently indicates a motor vehicle tilting movement about the motor vehicle longitudinal axis.  
     
     
       2. The device according to claim  1 , wherein said inclination sensor is an inclination switch. 
     
     
       3. The device according to claim  1 , which comprises a housing enclosing said rate-of-rotation sensor ( 1 ) and another housing enclosing said inclination sensor ( 2 ). 
     
     
       4. The device according to claim  3 , including an evaluation circuit for evaluating the rotation output signal and the inclination output signal, said evaluation circuit being connected to said rate-of-rotation sensor, said inclination sensor, and said triggering device, and being disposed in one of said housings different from said housings holding said rate-of-rotation sensor and said inclination sensor. 
     
     
       5. The device according to claim  1 , including an evaluation circuit for evaluating the rotation output signal and the inclination output signal, said evaluation circuit connected to said rate-of-rotation sensor, said inclination sensor, and said triggering device. 
     
     
       6. A method for triggering an occupant protection system when a motor vehicle tilts about a motor vehicle longitudinal axis, which comprises: 
       measuring a rate of rotation of the motor vehicle about the motor vehicle longitudinal axis;  
       measuring an angle of inclination of the motor vehicle; and  
       triggering the occupant protection system only if both the measured rate of rotation, and the measured angle of inclination exceed given values and blocking the triggering of the occupant protection system when a measured angle of inclination and a measured rate of rotation initially indicate a stable tilted position of the motor vehicle, and a subsequently measured rate of rotation indicates a rotation of the motor vehicle.  
     
     
       7. A method for triggering an occupant protection system when a motor vehicle tilts about a motor vehicle longitudinal axis, which comprises: 
       measuring a rate of rotation of the motor vehicle about the motor vehicle longitudinal axis;  
       measuring an angle of inclination of the motor vehicle; and  
       triggering the occupant protection system only if both the measured rate of rotation, and the measured angle of inclination exceed given values and blocking the triggering of the occupant protection system when a measured angle of inclination from an inclination sensor and a measured rate of rotation from a rate-of-rotation sensor initially indicate a stable tilted position of the motor vehicle, and a subsequently measured rate of rotation indicates a rotation of the motor vehicle.  
     
     
       8. A method for triggering an occupant protection system when a motor vehicle tilts about a motor vehicle longitudinal axis, which comprises: 
       measuring a rate of rotation of the motor vehicle about the motor vehicle longitudinal axis;  
       measuring an angle of inclination of the motor vehicle; and  
       triggering the occupant protection system only if both the measured rate of rotation, and the measured angle of inclination exceed given values and blocking the triggering of the occupant protection system when a measured angle of inclination and a measured rate of rotation initially indicate a tilted position of the motor vehicle lasting longer than a predetermined time interval and a subsequently measured rate of rotation indicates a rotation of the motor vehicle.